Python: How to exclude words from regular expressions

Question

I want to use regular expressions to remove the letter "t" from the end of each word w in a string ,unless the word is "it" or "at".
Below is my code and while it works, I wonder, if there is a more elegant way to code this.

import re

str = ("wombat", "it", "belt", "at", "adult")

words= str. split()
for w in words:
if w != 'it' and w != 'at':
w = re.sub(r't

Answer 1

import re

words = 'wombat it belt at adult test_word'
print(re.sub(r'(\w+)(?<!\b[ai])t\b', r'\1', words)) # womba it bel at adul test_word

Answer 2

A variation on Russ solution:
sub(r'(?<!\b[ia])t\b', '', test)

to explain:
\b means a boundary that encloses words, an invisible marker before or after any word.
[ia] mean either i or a character
(?<!X)Y is called a negative lookbehind. Just search for this term online to learn more. It causes the expression to match Y only, if X is not found directly before Y.

https://docs.python.org/3.8/library/re.html

Also, you can solve this without regexp, see in my code a solution with list comprehension.
https://code.sololearn.com/cU5Lf6FqRpXW/?ref=app